How about building an 80-foot dock in Portland’s Back Cove that leads to a 900-square-foot floating platform with walls that raise and lower with the tides? Nothing if not clever if it works, right? I’m all for it.

The Portland nonprofit TEMPOart has proposed commissioning Massachusetts artist Matthew Mazzotta to do just that: design and build a kind of floating conference room called “Shifting Tides” off Back Cove Park, that littoral parking area across from the Forest Avenue Hannaford store. The idea would be for the unique structure to serve as an event space and meeting place for people from all walks of life to discuss issues of community.

The last time a Massachusetts artist was commissioned to create a site-specific work in Portland, of course, it was a disaster.

Shauna Gillies-Smith’s “Tracing the Fore” project, which used grass and metal waves to mark where the water’s edge was before the harbor was filled in to create Commercial Street, became an Old Port eyesore and had to be removed. But one of the virtues of “Shifting Tides” is that it would only be up for five months. So even if Mazzotta’s kinetic contraption doesn’t float, the annoyance will only be temporary.

Back Cove is a defining feature of Portland’s urban landscape. It is Portland’s mirror, the shallow 340-acre tidal basin opening a sweeping suburban vista from Interstate 295 and framing the panoramic view of the peninsula skyline from Baxter Boulevard. An artificially enhanced landscape, Back Cove consists of a lot of filled land and was Mayor James Baxter’s 19th-century vision of a sylvan seaside park. Today, the path around the cove is popular with joggers, strollers and dog walkers.

Back Cove has been the focus of big ideas for more than a century. The biggest dreamer was James Phinney Baxter (1831-1921), father of Percival Baxter (whose Baxter State Park was an even bigger dream) and a six-term mayor of Portland. Baxter, too, turned to Massachusetts professionals – the heirs to Frederick Law Olmsted’s design firm, to articulate his vision of an emerald necklace of parks.

Just as I am sure the Mazzotta project will attract its share of critics, Baxter was seen by some in his day as an elitist, his big ideas for beautifying Back Cove having been a factor is his being voted out of office in 1897 and 1905.

Back Cove proposals continued in the 1920s and 1930s, one of the most ambitious being the 1938 grand scheme devised by architects Myron Lamb and John Calvin Stevens II. Their plan for an Eastern Civic Center along the cove included a beach, wading pool, swimming pool, arcade, concession stand, cafeteria, boathouse and youth hostel. Instead of blossoming as a recreational amenity, however, Back Cove remained a scenic open cesspool until 1976 when a wastewater treatment plant was built at the foot of the Eastern Promenade.

Last year five design firms entered blue-sky proposals in a design challenge aimed at revitalizing Portland’s Bayside neighborhood. (Which really ought to be called Coveside, since it is beside Back Cove, not Back Bay.) Re-imagining Back Cove figured prominently in several of the proposals.

Michael Boucher and Patrick Costin, contemplating the effects of climate change and sea-level rise, proposed “severing the cove from the ocean by means of a dam” to turn Back Cove into Back Cove Pond. Soren Deniord, Richard Lo and Danielle Foisy didn’t go quite that far, proposing not a freshwater makeover, but a tidal barrier beneath Tukey’s Bridge that would manage tides and storm water runoff, produce electricity and create a reversing falls for kayakers.

Mazzotta’s Shifting Tides is more about social than hydro engineering. His past projects at the intersection of art and social activism include a house in Alabama that opens transformer-like into a theater, a storefront in Nebraska that also folds out into a theater and a dog waste receptacle in Massachusetts that generates methane to power a street lamp.

“Shifting Tides,” which would resemble a tide-activated Chinese takeout box the size of a house, would be a temporary public space. Last week, TEMPOart announced it would have to delay “Shifting Tides” for a year owing to unforeseen engineering challenges. Like I said, clever if it works.

It will be easy for naysayers to foresee problems with “Shifting Tides,” ranging from marring the pseudo-natural beauty of the cove to inviting vandalism and misadventure. Portland already has the occasional tipsy tourist falling into its harbor and drowning, so it’s easy to imagine someone wandering out of Bayside in an intoxicated state onto the Back Cove dock and falling in.

But as long as it’s temporary and paid for with private funds, I say go for it. Back Cove is big enough to handle it.

Freelance journalist Edgar Allen Beem lives in Brunswick. The Universal Notebook is his personal, weekly look at the world around him.